Exposure to green light could help those who suffer migraine and post-traumatic headaches, according to a new study.

Writing in the journal Brain, researchers from Harvard Medical School say “pure-wavelength green light” helps ease sensitivity to light, called photophobia, and can reduce the intensity of headaches.

The researchers say more than 80 percent of migraine sufferers have photophobia, leading many to seek relief by isolating themselves in a dark room, unable to perform daily tasks.

“It is their inability to endure light that most often disables them," says Rami Burstein, Professor of Anesthesia at Beth Israel Deaconess Medical Center (BIDMC) and Harvard Medical School, and lead author of the study.

For the study, researchers asked patients experiencing a migraine to report how different color and intensities of light impacted their headache. At the light levels of a typical office, the patients reported that of blue, green, amber or red lights, all but green made their headaches worse.

Researchers said patients reported that green light reduced the intensity of their pain by about 20 percent.

The reason: Green light appears to create the least amount of electrical signals generated by the eye’s retina and brain’s cortex.

"My hope is that patients will be able to benefit directly from these findings one day very soon," said Burstein, who is trying to devise an economically viable light bulb that can emit “pure green light at a low intensity.” He also envisions sunglasses that can block out all light but green.